Process and apparatus for producing convex and concave surfaces in stone



M. E. JONES Aug. 2, 1932.

PROCESS AND APPARATUS FOR PRODUCING CONVEX AND GONCAVE SURFACES IN STONE Filed March 20, 1931 5 Sheets-Sheet l M. E. JONES Aug. 2, 1932.

PROCESS AND APPARATUS FOR PRODUCING CONVEX AND CONCAVE SURFACES IN STONE Filed March 20. 1931 3 Sheets-Sheet 2 M. E. JONES 1,869,427

PROCESS AND APPARATUS FOR PRODUCING GQNVEX AND CONCAVE SURFACES IN STONE Aug. 2, 1932.

Filed March 20, 1931 3 Sheets-Sheet 3 M w F MES.

r 1 and much labor.

Patented Aug. 2, 1932 MARSHALL E. JONES, OF ST. CLOUD, MINNESOTA PROCESS AND APPARATUS FOR PRODUCING CONVEX AND CONCAVE SURFACES IN STONE Application filed March '2l), 1331. Serial No. 523,976.

portions of stones to leave upstanding de-- signs in relief thereon. The edges of the design portions of the stone are out straight inwardly into the stone, inasmuch as it is impossible to curve or round these edges when the sand blast is used with the ordinary stencil fixed to the face of the stone. To

round the edges of the portions of the stone standing in relief from the background of the stone, it has hitherto been necessary to use hand tools or to use what may be known as a step stencil sand blast process. vTo

round the edges of the upstanding portions of the stone to produce the rounded natural appearance of flowers, leaves and countless other designs in the stone by the hand method necessitates extremely skillful workmanship The hand method is slow and tedious and necessitates such expense that monument companies and others very rarely employ this hand method unless special work for which large charges can be made 1s to be done.

The other method used which I call the step stencil method, is practically as difficult, tedious and expensive and requires skilled workmanship. In this step stencil method, a stencil is first applied to the stone and a sand blastis directed against the stencil to cut out portions of the stone. The various edges of the. stencil are then cut down somewhat and the sand blast is again applied against the stencil to make 40 outs in the stone in portions thereof previously covered by the stencil. The stencil is then a second time and often a third time cut away at its edges and the sand blast is successively applied against the same before the desired rounded effect can be given to the edges of the portions of the stone standing in relief from the cut away back ground.

It is generallythe object ofthis invention to provide a novel process and a novel apparatus for carrying out the process, whereby convex and concave surfaces may be quick- "ly cut in stone and similar material by unskilled workmen using a sand blast, and whereby the edges of portions of the stone standing in relief from a background may be rounded to produce designs in the stone having a natural and life-like appearance.

To this end the invention consists in the novel processes and novel steps in processes and the novel apparatus and novel parts of apparatus hereinafter defined in the claims v and described inthe following specification, made in connectlon with the accompanylng drawings, wherein one apparatus for carrying out the processes of the invention is illustrated and wherein, V

. Fig; l is a View in front elevation of the apparatus, certain of the parts being broken away and other parts, being shown in vertical section;

Fig. 2 isa vertical section taken on the line 22 of Fig. 1 as indicated by the arrows;

Fig. 3 is a horizontal section taken on the line 33 of Fig. 2, as indicated by the arrows;

Fig. 4 is a vertical section taken on the line' l l of Fig. '3, as indicated by the arrows,

"Fig. 5 is a View illustrating in detail,

' certain of theparts shown in Fig. 1;

Fig.- 6fis a vertical section taken on the line 6-6 of Fig. 5, as indicated by the arrows;

Fig. 7 is'a view in front elevation of a stone witha stencil applied thereto for use in connection with a sand blast, to make certain entering cuts in the stone;

Fig. 8 is a section taken on the line 88 Fig. 12 is a'section taken on the line 12- 12 of Fig. 11, as indicated by the arrows, Figs.

11 and 12 showing the work that can be done by use'of my processes and apparatus.

Although my processes can be carried out L; by use of various apparatus, the apparatus illustrated can be successfully used. The apparatus will be first described, whereupon my processes can be more readily described in connect on with the use of the apparatus shown.

Referring to the drawings, there is illustrated a casing 13 closed by removable plate 14 and having an upwardly extending hub within which a vertical tube 15 is mounted.

A base plate 16 is also provided having an from adjacent faces of the two housings.

The two housings have similar forwardly projecting hubs 23 disposed at the same level. Mounted in the casing 13 as on the base thereof, is an electric motor 24 having an armature shaft carrying a pinion 25 which meshes with a gear 26 mounted on a shaft 27 supported in suitable hearings in the casing 13. The shaft 27 carries beveled pinion 28 at one end meshing with a beveled gear 29 mounted on a long vertical shaft 30 which is journaled in the base of the casing 13 and in the upper end of the housing 18 and which projects vertically through the casing 13, tube 15 and housing 18. The shaft 30 carries, adjacent its upper end within the housing 18, a beveled pinion 31 which meshes with a beveled gear 32 at one end of a horizontal shaft 33 extending through tube 22 and journaled within bearings 34 therein. At its opposite end from the gear 32, the shaft 33 carries a beveled pinion 35 meshing with a beveled gear 36 mounted on a short vertical shaft 37 located within and journaled in the housing 19. Forwardly projecting shafts 38, horizontally disposed, are journaled within the forwardly projecting hubs 2-3 and each of these shafts carries a bevel gear 39 at its rear end. The vertical shaft 30 carries a beveled pinion 40, which meshes with the gear 39 located within the housing 18 above the shaft 38 journaled within the hub 23 of the said housing 18, while the shaft 37 carries a beveled pinion 41 which meshes with the beveled gear 39 located within the housing 19 below the shaft 38 mounted within the hub 23 for the said housing 19. lVith the construction provided, it will be seen that both of the shafts 38 will be driven at the same speed and in the same direction. Various other means than that illustrated may he used for driving these two shafts 38 at the same speed and in the same direction.

Applied to the forward and outer ends of the two shafts 38, as best illustrated in Fig. 6, are crank arms 42. These crank arms 42 have hubs secured to the forward ends of the shafts 38 and have openings 42a out wardly disposed from the hubs. Slots 426 are provided in the crank arms 42 and bolts 43 forming pivots extend through the slots 42b and are adjustably held on the crank arms by means of nuts 44 and 45, which abut opposite sides of the slotted portions of the crank arms. The openings 42a are provided in the crank arms in order that ready access may be had to the nuts 45 for loosening or tightening the same with a wrench. The radial displacement of the bolts 43 from the longitudinal central axes of the shafts 38 may be readily adjusted by loosening the nuts 45 and moving the bolts 43 in the slots 42b to or from the axial center lines of the shafts 38. v

A pair of heads 46 have portions cut away therefrom to form both vertical and horizontal openings therethrough, and short central bar portions 46a at their lower edges. Blocks 47 fit within the vertical openings of the heads 46 and the bolts 43 are journaled within these blocks. The blocks 47 rest on the bar portions 46a and have central ends bearing against shims 48 and outer ends against which wedges 49 bear. The shims 48 and wedges 49 project through the vertical openings in the heads 46. The two heads 46 are interconnected by a hanger bar 50 which has rod portions at its two ends swivelled within the heads 46, so that the hanger bar may turn about a horizontal axis. The hanger bar has an upper oppositely beveled edge which forms a track upon which a pair of brackets 51 may ride. These two brackets 51 have passages extending t-herethrough and through which the bar 50 projects, and the brackets may be held in any desired fixed position on the bar by means of set screws 52. The brackets have portions which depend downwardly and preferably somewhat forwardly from the hanger bar 50 and arms 53 are secured to the dependent portions of the brackets as by being received within slots cut therein. The arms 53 are held in the slots of the brackets as by means of set screws 54. A. horizontal screw 55 is secured in brackets 56 which depend downwardly from the two ends of the hanger bar 50 and this screw extends through laterally spaced portions of the brackets 51. Wheeled nuts 57 mounted on screw 55 fit between the spaced portions of the brackets 51 and it will be seen that when the set screws 52 are loosened and the nuts 57 are turned, sliding movement may be given to the brackets 51 and parts carried zontal cross section and have rack teeth 58 cut therein. Blocks 59 preferably made in two sections held together and having T- shaped Openings extending vertically therethrough within which the arms 53 fit, are applied to the arms and each block has a short cross shaft 60 journaled therein and carrying a pinion 61 located within a recess within the block and meshing with the rack teeth 58. The shafts 6O carry wheels 62 at their outer ends and it will be seen that by rotating the wheels 62, the blocks may be raised or lowered on the arms 53. Set screws 63 are used to lock the blocks to the arms 53 when the blocks have been adjusted to the desired level. Each block has a forwardly to rearwardly extending hub at its inner side within which a rod 64 is extensibly mounted. l/Veights 65 are carried by the forward ends of these rods 64 and these weights will, tend to swing the arms 53 and hanger bar 50 rearwardly or toward the stone A which will be placed behind the blocks 59. The swivelled connections between the hanger bar 50 and the heads 46 will permit of this swinging movement. The rear ends of the rods 60 have flattened circular portions 6% provided with radial corrugated grooves on one face and connected to the flattened circular portions 64a by wing nut equipped bolts 64?) are the angularly bent clamp members 66. These clamp members 66 may be formed as best illustrated in Figs. 1, 2 and 3, for cooperation with clamp members 67 secured to the upper and lower portions of clamp members 66 by wing nut equipped bolts 68. Clamp members 66'and 67 are adapted to hold a stencil such as the stencil B. As the rods 64 may be extended varying distances rearwardly from the blocks 59, adjustment of these rods may be made to meet the requirements for their use in connection with working a particular stone, such as the stone A. The rods 6 L may be locked in adjusted position on the block 59 by means of set screws 59a. Angular adjustment of the clamps formed by the clamping members 66 and 67 can-be made relative to the rods 64: so that the stencil B held by the clamps may be disposed at the proper inclination to correspond .to the face of the particular portion of the stone A being worked.

With the machine described, it will be seen that when the motor A is set in operation,

the two shafts 38 will be driven to rotate in the same direction at the same speed. The crank arms 42 will accordingly be'similarly rotated and the h anger bar 50 and all parts carried thereby will be gyrated. The radius of gyrationof the hanger bar and the parts carried thereby will be determined'by the spacing between the bolts 4L3 and the longitudinal axes of the shafts 38. Proper adjustment of the two arms 53 relative to each other, may be made by turning the wheel nuts 57 after the set screws 52 are released, so that the clamps 6667 will be properly spaced to engage the corners of the stencil B supported thereby. The stone A to be worked on will be located rea'rwardly from the arms 53 and the weights 65 will tend to swing the arms 53 so that the stencil B bears against the stone. The blocks 59 may be adjusted vertically by means of the wheels 62, so that the stencil A will be located at exactly the proper heightrelative to the stone A, and the rods 64; may be extended inwardly or outwardly from the blocks 59 so that the stencil may be properly positioned adjacent he portion of the stone to be worked. The

practically no vibration will be imparted to the stencil. B when the motor is in operation. As a result, the stencil B will be gyrated in a true circular path.

Let us consider that it is desired to cut away portions of the stone A to leave the figure C standing in relief from the background of the stone as shown in Figs. 11 and 19.. Let us further consider that the stone A has a polished surface which it is not desired to mar. v process is to apply a protecting stencil designated by the letter D and illustrated in Figs. land 8, to the face of the stone that is to be worked. This protecting stencil D will be glued or otherwise secured to the face of the stone and will be composed of material impervious to asand blast. The stencil D and all the other stencils hereina 'ter and the particular des gn illustrated is circular and for this reason the protecting stencil Dis shown as havlng a circular opening 69 The first step in my The protecting stencil D will be therein; I glue or otherwise'apply to the portion of the face of the stone A within the opening 69 of the protecting stencil D What I call a. primary stencil E. This primarystencil may be cut as shown for producing the particular figure C. Narrow openings are provided in the primary stencil E which outline a figure corresponding generally to the edges of the ultimate figure C to be made. After the two stencils D and E have been applied to the stone, the primary stencil E is subjected to the action of a sand blast, which will cut away portions of the stone not covered by either the stencil D or the stencil E and thereby leave entering grooves in the stone as best shown in Fig. 8. After the grooves 70 are cut in the face of the stone, the primary stencil E is removed from the face of the stone. lVIy gyrating stencil B best illustrated in Figs. 9 and 10, is now brought to position over the face of the stone. The gyrating stencil used for producing the figure C, is formed as shown in Figs. 9 and 10 and may consist of an outer section B which may be of rectangular shape to be properly held in place by the clamps 66 67 and an inner section B which will fit within the opening 69 of the protecting stencil. The machine carrying the stencil B will be properly adjusted at the time the gyrating stencil is applied thereto to permit proper positioning of the stencil B over the portion of the stone to be worked. The machine will then be set in operation and the stencil B will be gyrated with a circular motion directly over the portion of the stone to be worked. A sand blast will be directed against the stencil B while it is being gyrated and the stone will be cut out by this sand blast to produce the figure C in relief from a background cut in the stone. The edges of the upstanding portion of the figure C will be rounded as indi cated by the stipling Fig. 11, and as shown clearly in Fig. 12. The rounded effect is produced due to the gyrating action of the stencil B. As the sand blast is played against the stencil B, certain portions of the stone will not be covered at any time by the stencil and these portions will be cut away the most to produce the background 71 of the figure C. Other portions of the stone will be covered at all times by the stencil and as a result, the sand blast will not cut away these portions and these portions designated 72 will remain substantially flush with the original surface of the stone. Between the portions 72 and the background portions 71, there are certain portions of the stone designated 73 that will be covered part of the time by the stencil B and uncovered part of the time by the stencil and as a result, the curved surfaces shown will be produced.

It will be understood that I do not wish to limit myself to the use of the particular machine illustrated and described for gyrating the stencil B. The stencil may be gyrated by any desired means. For producing certain designs in the stone, I may desire to impart other than a circular gyrati motion to the stencil B. Thus it'may be desirable to reciprocate the stencil B for certain purposes and to produce certain eifects in the stone. hile at the present time it is thought desirable to use the primary stencil E to make the entering grooves 70 in the stone, so that when the sand blast is applied to the gyrating stencil B, the sand may quickly cutthe stone by working first into the grooves 70, I may eliminate the use of the primary stencil E entirely and use only the gyrating stencil B. The protecting stencil D serves to protect a polished face of the stone from the action of the sand blast. It is not essential however, that I use the protecting stencil D, and in some situations it will be undesirable to use the same. The various designs and figures that may be cut in the stone are, of course, innumerable. In producing certain designs it is desirable to use two or more different gyrating stencils and to super-impose a. figure produced by one of the gyrating stencils on a figure produced by another gyrating stencil. It may also be desirable to use two gyrating stencils simultaneously wi h a sand blast to produce certain effects. I consider it to be within the scope of my invention to vary the steps in my process considerably.

it wil be seen that designs of various types may be quickly cut in stone by unskilled workmen and these designs will stand in relief from a background cut in the stone and the edges of the outstanding portion of the design will be both concavely and conveXly curved. With my presentproccsses and apparatus, curved relief Work may be produced in stone practically as easily as it has hitherto been possible to produce uncurved relief work. By varying the radius of rotation of the gyrating stencil, the curvature of the edges of the relief work may be considerably varied.

It will, of course, be understood that various changes may be made in my processes and in the various steps of the processes and various changes may be made in the form, details, arrangement and proportion of the apparatus described without departure from the scope of the present invention.

Attention should be called to the fact that in the machine illustrated, the use of the shims 4:8 and the wedges d9 will permit adjustnient of the position of the blocks l? in the heads l5 to take up for variations that may take place between the centers of the bolts 43 due to temperature changes or atmospheric conditions.

hat is claimed is 1. The process of producing curved edged figures in relief in stone which consists in gyrating a stencil over the stone and directing a sand blast against the stencil to out way portions of the stone not covered by the stencil.

2. The process of producingcurved edged figures in relief in stone which consists in gyrating a stencil over the stone while directing a sand blast against the stencil to cut away portions of the stone not covered by the stencil, and varying theradius of gyration of the stencil to produce varying curvatures in the edges of the figures.

3. The process of producing curved edged figures in relief in stone which consists in first applying a protecting stencil having an opening therein to the stone and then gyrating a second stencil over the portion of the stone exposed by the opening in the protecting stencil while directing a sand blast against the second stencil to cut out portions of the stone not covered by either stencil.

4. The process of producing curved edged figures in relief in stone which cons ts first in applying a primary stencil directy to the stone, directing a sand blast against the stencil to malre entering cuts in the stone then removing theprimary stencil and then ing a second stencil over the portions of the stone exposed by removal of the primary stencil while directing a sand blast against the gyrating stencil.

5. The process of producing curved edged figures in relief in stone which consists first in applying a protecting stencil having an opening therethrough to the face of a stone, applying a primary stencil to the portionof the stone eXposedby the opening in the protecting stencil, directing a sand "last against the primary stencil to produce entering cuts in the stone, removing this primary stencil and then gyrating a third stencil over the portion of the stone exposed by removal of the primary stencil while directing a sand blast against the third stencil.

6. The process of producing curved edged figures in relief in stone which consists in gyrating a stencil over the stone, forcing said stencil against the stone while directing a sand blast against the stencil to cut away portions of the stone not covered by the stencil.

7. An apparatus for use with a sand blast for producing curved edged figures in relief in stone, comprising a stencil, means for holding said stencil over a portion of the stone to be worked and means for gyrating said holder and stencil.

8. An apparatus for use with a sand blast for producing curved edged figures in relief in stone, comprising a stencil, means for holding said stencil over a portion of the stone to be worked, means for gyrating said holder and stencil and means for varying the radius of gyration of said stencil and holder.

universal adjustment on said member whereby a stencil may besupported by said stencil holder and a sand blast maybe directed against the stencil.

10. An apparatus'of the class described, comprisinga supporting structure, a pair of shafts journaled at spaced points in said supporting structure, means for driving said shafts, a pair of members eccentrically connected to said shafts for gyrationthereby, a bar swivelledin saidniembers, and carried thereby, an arm carried by said bar, a stencil carried by. said arm for positioning over the face-of a stone andmeans' urging said stencil to swing inwardly toward the'face of a-stone located behind the stencil.

11. An apparatus of the class described, comprising a supporting structure, a pair of shafts. journaled at spaced points in said structure, means for 'drivingsaid shafts, a

pair of heads eccentrically connected to said shafts respectively for gyration thereby, a bar swivelled in said members, an arm carried by, said bar, a bloclrmounted for vertical adjustment on said arm, a stencil holder mounted on said block and a stencil carried by said stencil holder adapted to be positioned over a portion of a stone to be worked.

12. An apparatus of the class described, comprising a supporting structure, a pair of shafts journaled at spaced points in said supporting structure, means for driving said shafts, a pair of heads eccentrically connected respectively to said shafts for gyration thereby, a bar mounted in said heads and interconnecting the same, an arm mounted on said bar, means for moving said arm longitudinally of said bar, and a stencil carried by said arm and adapted to be positioned over a portion of a stone to be worked.

13. An apparatus of the class described, comprising a supporting structure, a pair of shafts ournaled at spaced points in said supporting structure, means for driving said shafts, a pair of headseccentrically connected to said shafts for gyration thereby, a hanger bar interconnecting said heads and swivelled therein, an arm supported from said hanger bar and depending downwardly therefrom, a block mounted on said arm for vertical adjustment, a substantially horizontally disposed rod mounted in said block for longitudinal extension inwardly therefrom, a stencil holder carried by said rod, a stencil carried by said stencil holder and adapted to be positioned over a stone to be worked and means urging said arm, block, stencil holder and stencil inwardly toward the stone.

14. An apparatus of the class described, comprising a supporting structure, a pair of shafts journaled at spaced points in-said structure in parallel relation, a hanger bar eccentrically connected at its ends to said shafts for gyration-ethereby, a pair of arms mounted on said bar for movement longitudinally of the same and extending downwardly from said bar and stencil holders carried by said arms.

15. The structure defined in claim 14, said stencil holders including blocks mounted for vertical adjustment on said arms, rods carried by said blocks and stencil clamps carried by said rods.

16. An apparatus of the class described, comprising a supporting structure, a pair of shafts journaled at spaced points in said sup porting structure, means for driving said shafts, a pair of heads eccentrically connected to said shafts respectively for gyration thereby, a horizontal hanger barinterconnecting said heads and swivelly mounted therein, a pair of arms mounted for sliding movement v on said hanger bar, blocks mounted for vertical adjustment on said arms, rods mounted for extensible adjustment in said blocks, clamps carried by said rods and a stencil held by said clamps.

In testimony whereof I affix my signature.

MARSHALL E. JONES. 

